Do not rely on the ordering or completeness of the values as new ones may be defined in the future! If you need to compare types, use hwloc_compare_types() instead.

Enumerator

HWLOC_OBJ_SYSTEM

Whole system (may be a cluster of machines). The whole system that is accessible to hwloc. That may comprise several machines in SSI systems like Kerrighed.

HWLOC_OBJ_MACHINE

Machine. The typical root object type. A set of processors and memory with cache coherency.

HWLOC_OBJ_NODE

NUMA node. A set of processors around memory which the processors can directly access.

HWLOC_OBJ_SOCKET

Socket, physical package, or chip. In the physical meaning, i.e. that you can add or remove physically.

HWLOC_OBJ_CACHE

Cache. Can be L1i, L1d, L2, L3, ...

HWLOC_OBJ_CORE

Core. A computation unit (may be shared by several logical processors).

HWLOC_OBJ_PU

Processing Unit, or (Logical) Processor. An execution unit (may share a core with some other logical processors, e.g. in the case of an SMT core).

Objects of this kind are always reported and can thus be used as fallback when others are not.

HWLOC_OBJ_GROUP

Group objects. Objects which do not fit in the above but are detected by hwloc and are useful to take into account for affinity. For instance, some operating systems expose their arbitrary processors aggregation this way. And hwloc may insert such objects to group NUMA nodes according to their distances.

These objects are ignored when they do not bring any structure.

HWLOC_OBJ_MISC

Miscellaneous objects. Objects without particular meaning, that can e.g. be added by the application for its own use.

HWLOC_OBJ_BRIDGE

Bridge. Any bridge that connects the host or an I/O bus, to another I/O bus. Bridge objects have neither CPU sets nor node sets. They are not added to the topology unless I/O discovery is enabled with hwloc_topology_set_flags().

HWLOC_OBJ_PCI_DEVICE

PCI device. These objects have neither CPU sets nor node sets. They are not added to the topology unless I/O discovery is enabled with hwloc_topology_set_flags().

HWLOC_OBJ_OS_DEVICE

Operating system device. These objects have neither CPU sets nor node sets. They are not added to the topology unless I/O discovery is enabled with hwloc_topology_set_flags().

HWLOC_OBJ_TYPE_MAX

Sentinel value

Function Documentation

Types shouldn't be compared as they are, since newer ones may be added in the future. This function returns less than, equal to, or greater than zero respectively if type1 objects usually include type2 objects, are the same as type2 objects, or are included in type2 objects. If the types can not be compared (because neither is usually contained in the other), HWLOC_TYPE_UNORDERED is returned. Object types containing CPUs can always be compared (usually, a system contains machines which contain nodes which contain sockets which contain caches, which contain cores, which contain processors).

Note

HWLOC_OBJ_PU will always be the deepest.

This does not mean that the actual topology will respect that order: e.g. as of today cores may also contain caches, and sockets may also contain nodes. This is thus just to be seen as a fallback comparison method.

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